Improving the Performance of Concrete with Internal Curing (Part 1)-Concept, Proportioning, and Aggregate (Recorded Presentation)

Video Transcription

Video Summary

This module focuses on internal curing for concrete, a topic that differs from traditional curing methods. Internal curing involves incorporating lightweight aggregates within concrete to provide additional moisture, critical for proper hydration and strength development, especially in high-performance concretes with lower water-to-cement ratios. Traditional curing typically relies on external water supply methods like ponding or water-retention membranes placed externally.<br /><br />The module outlines the scientific basis for internal curing, including the role of porous lightweight aggregates which store water and release it as needed. Mixture proportioning principles are key, where the volume of water needed to offset chemical shrinkage (a process where reactants' volume exceeds resultant products during hydration) is calculated, ensuring that sufficient moisture is available internally.<br /><br />The guide also delves into the properties of aggregates used and testing methods (e.g., desorption and absorption tests) to determine suitable attributes for internal curing. Practical examples and a spreadsheet assist practitioners in calculating the necessary proportions for internal curing balances, while also addressing the potential benefits such as minimizing cracking due to self-desiccation. Moreover, it prepares for subsequent modules on shrinkage reduction and other properties enhanced by internal curing.

Keywords

internal curing

concrete

lightweight aggregates

hydration

mixture proportioning

chemical shrinkage

desorption tests

self-desiccation

high-performance concrete